1. Field of the Invention
The present invention relates to a method and an apparatus for outputting stereoscopic images. More particularly, the present invention relates to a method and an apparatus for enabling a mobile terminal to output a stereoscopic image including alternating left frames and right frames.
2. Description of the Related Art
With rapid popularization, mobile terminals have become a necessity of modern life. Mobile terminals have evolved into multimedia communication devices that can provide not only basic voice communication services but also various data transmission and supplementary services. Recent advances in a 3 Dimensional (3D) stereoscopic imaging technology have given rise to development of mobile terminals capable of outputting 3D stereoscopic images.
A 3D stereoscopic image includes a sequence of alternating left frames (L-frames) and right frames (R-frames). An L-frame and R-frame may be one of a key frame (I-frame) and a delta frame (P-frame).
During playback of a stereoscopic image, a mobile terminal outputs a sequence of L-frames and R-frames. When the user changes the playback position of the stereoscopic image, the mobile terminal starts decoding from an I-frame corresponding to the changed playback position. When the I-frame is an L-frame, the mobile terminal may create a desired stereoscopic effect by resuming playback of the stereoscopic image. However, when the I-frame is an R-frame, the mobile terminal may generate a reversed stereoscopic effect.
FIG. 1 illustrates an image with a desired stereoscopic effect and an image with a reversed stereoscopic effect according to the related art.
Referring to FIG. 1, a reference symbol [a] indicates an image with a desired stereoscopic effect, and a reference symbol [b] indicates an image with a reversed stereoscopic effect. As indicated by reference symbol [a], a sequence of an L-frame and an R-frame creates a desired stereoscopic effect, in which hearts 10 and 11 are seen as concave and a cross 12 is seen as convex. On the other hand, as indicated by reference symbol [b], a sequence of an R-frame and an L-frame creates a reversed stereoscopic effect, in which the hearts 10 and 11 are seen as convex and the cross 12 is seen as concave. In this case, content-specific stereoscopic effects may not be delivered to the user of a mobile terminal.
Therefore, a need exists for a method and an apparatus to output a stereoscopic image such that the stereoscopic effect intended by the content author is fully conveyed by a mobile terminal.